This Practice Point commentary discusses a study by Kastrup et al. that demonstrates that the early detection of blood-brain barrier (BBB) disruption as detected on post-contrast enhanced T1-weighted MRI after thrombolysis for acute ischemic stroke predicts subsequent intracerebral hemorrhage. No parenchymal enhancements were detected on scans before thrombolysis; however, after thrombolysis, 3 of 48 patients had parenchymal enhancement in the areas of the initial insult and these patients later developed symptomatic hemorrhages at these sites. These data suggest that assessment of BBB integrity might be a useful addition to a multimodal MRI study, potentially improving the overall efficacy of thrombolysis and broadening the effective time window. Further work is needed to optimize an imaging sequence that will be short and sufficiently sensitive to detect early damage to the BBB before treatment. Meanwhile, prudent clinicians should select patients for therapy on the basis of accepted guidelines and best clinical judgment.